1. Field of the Invention
The present invention relates to synthetic polymeric articles incorporating glass beads as filler material, and to glass bead filler materials for use in the preparation of such articles.
2. Discussion of the Art
It is well known to fill synthetic polymeric materials with glass beads. Depending on: (a) the specifications of the beads, (b) the treatment, if any, to which the beads are subjected before being mixed with the synthetic polymer or synthetic polymer precursor, and (c) the beads/synthetic polymer quantity ratio, the presence of the filler can facilitate working of the compounded material and can, in various respects, enhance some mechanical properties of articles formed from the material. Spherical glass beads, for example, are capable of improving stress distribution within moulded articles as well as facilitating the moulding process itself. All these facts are well known (see, e.g., "Glass microspheres: bubbles and beads as plastics additives" by Darrel L. Muck and James R. Ritter, Plastics Compounding, January/February 1979, page 12.
It is recognised in the art that while glass beads, used as a synthetic polymer filler, can result in some improvement in various mechanical strength properties of articles formed from the synthetic polymeric material, such as their flexibility and tensile strength, the presence of the beads often has an adverse effect on the impact strength of the articles. This is particularly the case when using solid, as distinct from hollow, glass beads.